Heating apparatus



Jan. 2, 1940.

E. J. DILLMAN HEATING APPARATUS 6 Sheets-Sheet I Filed June 5, 1936 INVENTOR JKALU ATTORNEY 1940? E. J. DILLMAN 2,185,978

' HEATING APPARATUS Filed June 3, 1936 6 Sheets-Sheet 2 IN VENTOR M;ATTORNEY Jan. 2, 1940. I DILLMAN 2,185,978

HEATING APPARATUS Filed June 3, 1936 6 Sheets-Sheet 5 v INVENTOR Jan. 2, 1940. E. J. DILLMAN HEATING APPARATUS Filed June 3, 1936 6 Sheets-Sheet 6 man mQ Q w n m 0 Q8 n3 a ma 3 m m Mn 0 N .mm m am Q1 5 2m 3 0. 3m 5 fin Mm U n m I E e an 1%? a; 3 ma r, h 8n m 3mm 5 5 Q NE 52 in A an 2 my g 9% WWW? E an 80 am am gm Sn man 63 m g. 2% Q8 A14.) ATTORNEY Patented Jan. 2, 1940 UNITED STATES 2,185,978 g HEATING APPARATUS Earnest J. Dillman, Detroit, Mich, assignor to Detroit Lubricator Company, Detroit, Mich, a corporation of Michigan Application June. 3, 1936, Serial No. 83,232

8 Claims.

My invention relates generally to heating systems and more particularly to control systems therefor.

One of the objects of my invention is to provide a new and improved control system for heating apparatuses and one which prevents the escape of heat via the furnace stack on the off" cycle of operation of the heating apparatus in a new and improved manner. Another object of my invention is to provide a new and improved control device for controlling the supplying of fuel to a heating apparatus.

Another object of my invention is to provide a control device of the above mentioned character having new and improved mechanism for throttling, and for seating a valve to control flow of fuel to the burner of a furnace in accordance with furnace temperature.

Another object of my invention is to provide a control device for controlling the supplying of fuel to the burner of a heating apparatus and also for controlling the operatibn of a damper.

Another object of my invention is to provide new and improved mechanism for actuating a control.

Another object of my invention is to provide new and improved mechanism for actuating adamper and also for controlling a circuit to the valve actuating mechanism to prevent opening of the valve when the damper is closed.

Another object of my invention is to provide new and improved mechanism for actuating the valve in accordance with the temperature of a room or other enclosed space to be heated.

Another object of my invention is to provide a new and improved tilt switch.

The invention consists in the improved construction and combination of parts, to be more fully described hereinafter and the novelty of which will be particularly pointed out and distinctly claimed; V v

In the accompanying drawings, to be taken as a part of this specification, I have fully and clearly illustrated my invention, in which draw- 45 lngs Figure 1 is a diagrammatic view of a heating apparatus and my new and improved control system therefor; v

Fig. 2 is a fragmentary view of the heating apparatus of Fig. 1 to show the preferable con struction of the furnace at the draft inlet;

Fig. 3 is a view in side elevation of a control associated parts of the device;

Fig. 4 is a top plan view of the control device of Fig. 3;

Fig. 5 is a view taken along the line 55 of Fig. 4 showing certain of the mechanism of the control device in cross section;

Fig. 6 is a View in cross section taken along the line 6-6 of Fig. 5;

Fig. 7 is a view shown in longitudinal central cross section of the control. device and taken along the line 'l-l of Fig. 4;

Fig. 8 is a perspective view of one of the parts of the control device;

Fig. 9 is a top plan view shown partly in cross section and partly in elevation. taken along the line 99.of Fig. 3;

Fig. 10 is a view of certain of the mechanism of the control device shown removed from the .casing;

Fig. 11 is an enlarged view shown in cross section and taken along the line H-Il of Fig. 9;

Fig. 12 is a view shown in cross section and taken along the line 12-12 of Fig. 11

Fig. 13 is a fragmentary top plan view of the mechanism shown in Fig. 10;

Fig. 14 is a view of a stack damper and my damper actuating mechanism shown partly in elevation and partly in cross section,- and Fig. 15 is a view looking from left to right of the damper actuating mechanism-of Fig. 14 and having casing portions broken away to show the arrangement of the operating and associated parts.

Referring to the drawings by characters of reference and first to Fig. 1, there is shown a heating apparatus, or furnace I having a fire box 2 in which a burner ,3 is located, the burner 3 being,

of the gas burning type, in the present instance. Fuel may be supplied to the burner 3 through a suitable supply line, or pipe 4. Disposed adjacent the burner 3 there is a pilot light burner 5 for lighting the burner 3, fuel being supplied to the pilot light burner through a supply line, orpipe 6, which may be connected in the main supply hne, as shown. The furnace includes a bonnet "1 in which is connected the usual stack 8 for the passage of the products of combustion to a chimney (not shown) for discharge to outdoor atmos-. phere. As is more clearly shown in Fig. 2, the furnace I is constructed having an externally disposed, box-likestructure IQ communicating with the fire box 2 through an opening in the side wall and at the base of the furnace I, the boxlike structure 10 having a top wall II provided with anopening constituting the draft inlet A plate-like damper member I 2 the furnace.

controls the draft inlet opening and may be pivoted, or hinged at one of its edges to the box-like structure |6. In the present instance, the damper I2 is disposed within the box-like structure 16 and is adapted to swing inwardly and downwardly to open position, as shown in dotted lines, or to open the draft inlet opening. The damper I2 is automatically operated by mechanism of the control system to be hereinafter described.

Associated with the heating apparatus is my control system therefor, which comprises in general a fuel supply control device l3, a stack damper control device l4, a room thermostat l5, and a tilt switch I6. Referring first to the construction of the fuel supply control device |3, this device includes a valve body |1 having oppositely disposed tubular bosses l8 and I9 defining the inlet and outlet, respectively, of the body, and these bosses may be internally threaded for connection in the main fuel supply line 4. The control device I3 is located in the fuel supply line 4 between the point of connection of the pilot light fuel supply line 6 and the main burner 3. As shown in Fig. '1, the valve body |1v has the usual internal wall 26 betweemthe inlet and outlet of the body, the wall 26 having a horizontal portion 2| in which there is provided a valve port 22 through which the gaseous fuel must flow to reach the main burner 3. The horizontal wall portion 2| preferably has an upwardly extending annular portion 23 around the valve port 22 to provide an upwardly facing seat for a reciprocalvalve member 24. The valve member 24 controls flow of gaseous fuel through port 22 to the main burner 3, and preferably includes a seat disc 25 of resilient materiaF-forcontack lar boss 26, and an annular external flange 28 for seating on the upper end of the tubular boss. The valve member 24 includes a stem 29 which extends vertically upward through the tubular boss 26 and extension member 21, the extension member being centrally bored to receive the stem 29 and guide the reciprocal valve member. Mounted on the upper end of the extension member 21 there is a casing 36 into which an upper end portion of the valve stem 29 extends. The casing 36 is preferably rectangular in shape having a top wall 3|,bottom wall 32, end walls 33 and 34, and side walls 35 and 36, which may be termed the front and rear walls respectively ofthe casing. The front wall 35 of the casing 36 is formed by a removable, plate-like cover that may be securedto the casing by screws, or by other suitable attaching means. Preferably the extension member 21 has an upper end reduced portion, as at 31, that extends through an aperture in the bottom wall 32 of the casing 36, the

reduced portion 31 providing an upwardly facing annular shoulder on which the bottom wall 32 of the casing seats. The reduced portion 31 of the extension member 21 extends upwardly above the inner face of the casing bottom wall 32, and is preferably threaded to receive a nut 36 for rigidly securing the casing 36 and extension member 21 together.

An upper end portion of the valve stem 29,

within the casing 36, is preferably externally threaded for receiving an internally threaded, tubular-shaped or cap-like member 39 that is preferably formed having an external annular flange 46 at its upper end to provide an enlarged, upwardly facing bearing surface. The extension member 21' has an enlarged bore 4| opening through its upper end, and disposed within bore 4| and seating on an upwardly facing shoulder therein is an abutment member 42 in the form of a washer having a central aperture through which the valve stem 29 extends. A coil spring 43 surrounds the valve stem 29 in bore 4| and has one end, or lower end, abutting the abutment member 42 and its other, or upper end, abutting the underside of the annular flange 46. The coil spring 43 is under compression tending, and operable to move the valve member 24 upwardly away from its seat, or toward open position.

The valve stem 29 has a centrally disposed, longitudinally extending, bored recess 44 that opens through the upper end of the stem and aligns with a relatively small and centrally disposed aperture in the upper end wall of the cap member 39. A coil spring 45 is disposed in the bored recess 44 with its-lower end abutting the recessed end wall thereof and with its upper end abutting a disc member 46. The disc member 46 is disposed in the bore 44 and the outer edge or periphery of the disc slidably engages the wall of bore 44. The coil spring 45 urges and is adapted to hold the disc member 46 against the underside of the upper end wall of the cap member 39, in overlying relation with the aperture therethroug'h. A manually operable .nrreans is preferably provided for seating and holding'the valve member seated, and may comprise a vertically extending stem*"48 adjustably screw threaded in the top wall 3| of the casing 36 in overlying relation to the upper end of the valve stem 29, and in axial alignment therewith. An upper end portion of the stem 48 projects externally of the casing, through the top wall 3| thereof, and may be provided with a knob or thumb screw 56 for rotating the stem. When the stem 48 is rotated to move and seat the valve, the lowerend of the stem passes through the aperture in the upper end of the cap member 39 and engages the movable disc member 46 which is moved downward compressing the coil spring 45. Through compression of the coil spring 45 the valve member 24 is moved downward, or toward its seat 23. It will be seen that the coil spring 45, when compressed, will serve to close the valve member 24 and hold it tightly against its seat, and due to its compressibility the spring 45 will also serve to prevent undue force being applied by the manual valve closing means, which might otherwise cause the resilient seat disc to be cut, or otherwise damaged.

It is to be understood that in Fig. 1 my system is illustrated with the various devices thereof in the positions they will assume before the heating apparatus is started. Likewise, the positions of the operating parts of the control device l3, shown in other figures of the drawings, are in the positions they will assume before the heating apparatus is started. The control device l3 includes mechanism for throttling the valve member 24 in accordance with variations inthe temperature of the heating apparatus, or furnace and for seating the valve member with a snapaction, and holding the valve member seated in the event of an undue increase in furnace temperature above a selectable temperature. This mechanism includes a temperature responsive power element, designated in general by the numeral 52, which is preferably mounted on the casing 36, externally thereof, and secured to the end wall 33 of the casing. The power element 52 includes a casing 53 that has an open end disposed toward the end wall 33 and overlying and closing an aperture or opening 54 in the end wall 33. The casing 53 is formed having an outwardly extending annular flange 55 at its open end for seating against the end wall 33, and in which flange apertures may be provided for receiving screws for rigidly securing the power element casing 53 to the main casing 30. A plate member 56 is positioned within and secured to the power element casing 53, the plate member 56 being disposed substantially parallel with the end wall 33 of casing 38. The plate member 56 is located adjacent the open end of the casing 53, or adjacent end wall 33, and is preferably formed having an annular flange 51 that is inturned relative to the casing 53 and engages the inner side Wall thereof. The annular flange 51 is to be secured and hermetically sealed to the inner side wall of casing 53 so that the joint therebetween will be fluid tight, and to this end solder, or other suitable means may be employed. The plate member 56 has a centrally disposed opening or aperture therethrough, and secured and hermetically sealed to a border portion of the plate member 56, around the aperture therethrough, is one end of a bellows member 58. The bellows member 58 is disposed in the casing 53, with its axis substantially transverse to the plate member 56, and the free endof-the-biellows-member 58 is secured and hermetically sealed to an end wall or plate member 60. The bellows member 58 and its casing 53 cooperate to provide an expansible chamber 6|. A conduit or tube 62 communicates with the expansible chamber 6| and may have one end secured in, and suitably fixed to, the side wall of the casing 53. The other end of the tube 62 is connected to a temperature responsive element or bulb 63 which may be connected to and secured in the wall of the bonnet 'l of the furnace see Fig. l. The bulb 63, expansible chamber 6|, and connecting tube 62 contain a fluid, such as methyl chloride, which is expansible and contractible in response to changes in temperature. Surrounding or wrapped around an end portion of the tube 62, adjacent its point of connection to the casing 53, there is preferably provided a coil of wire 64 for reenforcing the tube against breakage.

Carried by the movable end wall of the bellows member 58 there is a thrust-member 65 that extends centrally through the bellows and projects into the main casing 30' through the opening 54 in the end wall 33. The thrust member 65 may be suitably secured to the movable end wall 60 of the bellows 58 by providing the movable end wall with a centrally disposed aperture for receiving a reduced end portion of the thrust member, the end of which reduced portion may be peened over, as at 66, to tightly clamp the movable end wall 66 between the peened over portion 66 and the opposed annular shoulder formed by the reduced portion. Ad-

jacent the movable end wall 60, the thrust member 65 is provided with an enlarged portion 61 providing a shoulder 68 which faces inwardly or toward the fixed end of the bellows 58. A

- sleeve member, or collar 69 is carried by the thrust member 65 and is slidably movable thereon and longitudinally thereof, movement of the thrust member 65. Positioned within the main casing 30 there is a cup-shaped adjustable abutment member 12 into which the other, or inner end of the coil spring 1| extends and abuts an end wall 13 of the abutment member. The adjustable abutment member 12 is provided with a centrally disposed aperture in its end wall I3 for slidably receiving the thrust member 65. The

abutment member 12 is held in adjusted posi-' tion by mechanism to be hereinafter described, and by said mechanism the abutment member may be movable longitudinally of the thrust member 65 to vary the force exerted by the spring 1| opposing compression of the bellows 58. The bellows 58 is shown in its expanded. position, which is the position it will assume before the heating apparatus is started, but afterthe heating apparatus is started the bellows will becompressed and the shoulder 68 of the .thrust member 65 will be in engagement withkthe slidable collar 69, which will be held against the shoulder bythespringll.

The mechanism for adjustingand holding the spring abutment member 12 in adjusted position includes a lever member 14 that'is pivotally supported within the casing 30 adjacent the top wall 3| and end wall 33 thereof.-- The'shape of the lever member 14 is more clearly seen in the perspective view thereof, Fig. 8. The levermember 14 is of general U-shape, havinga substantially horizontally disposed connecting side immediately above or overlying the thrust member 65, and from which connecting side depend spaced, substantially parallel sides or lever arms I6. The sides or lever arms 16 straddle the thrust member 65 and also extend substantially parallel to the side walls of the main casing 38. Preferably the lever arms 16 are of general L-shape, as seen from a side view, Figs. 3 and 7, having portions 11 at their upper ends that extend toward the end wall 33 of the casing 30, adjacent which they have substantially parallel ears 18 that extend upward above the connecting side 15. The ears 18 are provided vwith aligned apertures for receiving a pin or shaft 80 on which the lever member 14 pivots, the shaft 80 being secured in the end wall 33 and extending longitudinally therethrough, as shown in Fig. 9. By pivotally supporting the lever member 14 at two spaced journal points on the shaft 86', it will be seen that rocking of the lever in planes through the longitudinal axis of the shaft is prevented. Adjacent their lower ends, the lever arms 16 are formed having extended edge portions 8| that extend toward the adjustable abutment member 12 and engagetherewith. The cup-shaped abutment member 12 is preferably formed having an external annular flange 82 ,at its open end, and in the flange 82, at spaced opposite points in a plane substantially horizontally through the longitudinal axis of the thrust member 65, are provided indentations 83, see Fig. 3, for receiving the extended portions 8|, the portions 8| preferably having pointed ends for seating in the indentations.

'A manually operable means is provided for adjusting and holding the abutment member I2 in adjusted position through the lever member I4, and is supported by the top wall ll of the casing 30 at a point immediately above the connecting side I5 of the lever member I4. In the top wall 3| of the casing there is provided a vertically extending bore that opens into the casing in overlying relation to the connecting side I5, an upper end portion of the bore, as at 86, being of enlarged diameter and opening through the upper outer wall surface of the top wall 3|. A tubular member or shaft 01 is adjustably screw threaded in bore 05 and has an upper end portion that extends upwardly above the top wall 3| of the casing 30. A knob 09 may be secured to the upper end of the tubular member 81 for gripping with the hand to rotate the shaft. An upper portion of the tubular member 81 is preferably internally threaded to receive an adjustment member in the form of a screw 09. The adjustment screw 99 has a downwardly extending stem portion 90 of reduced diameter whose lower end abuts the head ofa loosely disposed thrust pin 9| disposed within the tubular member 01 and extending longitudinally thereof. A lower end portion of the thrust pin 9| projects into the casing 30, and the lower end of the thrust pin 9| is preferably pointed to seat in an upwardly facing indented portion 9: in the upper face of the substantially horizontally disposed connecting side of the lever member I4. The indented portion 92 is preferably located substantially midway between the depending lever arms I0; The tubular member 01 is preferably provided with a reduced internal bore portion adjacent its lower end, providirig an upwardly facing shoulder 94 for engagement with the head of thrust pin 9I to limit downward movement of the thrust pin relative to the tubular member 01. It will be seen that through adjustment of the screw 09, whose lower end acts as an abutment member for the loosely disposed thrust pin 9 I the position of the thrust pin relative to the tubular member 01 may be adjusted, or changed. The tubular member 01 is provided, adjacent its upper end, with an integral and external gear 90 whose teeth mesh with gear teeth provided on the outer edge of a rotatable dial or plate member 91 that lies flat against the top wall ll of the casing 30. The dial plate 91 may be rotatable about a, screw 90 threaded into the top wall 3|, and preferably the top face of the wall II is slightly recessed to receive the dial plate. By rotating the tubular member 01 the lever member I4 will be pivoted, moving the spring abutment member 12 and thereby varying the force exerted by the spring 'II opposing inward movement of the thrust member 05. Thus, it will be seen that through adjustment of the position of the spring abutment member I2, the furnace bonnet temperature at which the power element is to overcome the spring II and move thrust member 05 inwardly can be selected. Suitable indicia may be provided on thedial plate at, and on the top wall 3| there maybe provided a flxed pointer 01 for cooperation with the indicia' fonindicating the furnace bonnet temperature at which the power element 52 will overcome the spring 'II. Within thabeilows 50. and surrounding the thrust mem-* ber .55, there is preferably provided a relatively light coil spring 99 having one endabutting the movable end wall 00 of the bellows 50 and the aremvs spring 99 maintains the adjustable abutment member I2 in engagement with the contact points of the lever member I4 when the control device is not in operation, as shown.

The power element 52 actuates the reciprocal valve member 24 -through lever mechanism that is disposed within the casing 80 between the power element and the valve member, and this lever mechanism includes a lever member I00 which is pivotally supported on a shaft IOI The casing 00, is constructed having an upstanding wall portion or boss I02 adjacent the cover 35, Fig. 3, and in the wall portion I02 and opposite side wall 30 there are provided aligned apertures in which the ends of the shaft IOI are secured. The lever member I00 is formed having a pair of spaced, substantially parallel lever arms. I03 and I04 that vare integral and are joined by and depend from a connecting portion I05 that extends substantially parallel with the end walls of casing 30. The lever arms- I03 and I04 are provided with aligned apertures adjacent their connecting portion I05 for receiving the shaft IOI. The connecting portion I05 has 9. depending extended portion I06 substantially midway between the lever arms I03 and I04, the extended portion I00 having a wall surface disposed toward the end wall 33, and provided with a conical recess I0'I to receive the pointed end I08 of the thrust member 65, see Figs. -7, 9 and 13. The lever member I00 includes a lever arm I09 that is integral with theconnecting portion I05 and extends therefrom at a point adjacent the lever arm I04, or adjacent the rear wall 36 of the casing 30 The lever arm I09 extends substantially horizontally toward the opposite end wall 04 of casing 30, and has a portion of its free end overlying the upper end of the tubular member or cap 39 that is carried by the valve stem 29. Carried by the lever member I00 there is I a leaf spring IIO which acts to hold the valve member 24 seated until the lever member I00 has pivoted through a predetermined angle in a counterclockwise direction, as seen in ,Figs. 3 and 7. The leaf spring H0 is disposed beneath and extends longitudinally of the lever arm I09 and has one end secured to the underside of the lever arm connecting portion I05. The leaf spring H0 is positioned so that a portion of its free end will bear on the upper face of the annular flange 40 of the valve member 24. Preferably the lever arm I09 is provided adjacent its free end with a downwardly projecting extended portion III which is adapted to engage with the upper-face of the leaf spring H0 at a point overlying or bearing on the annular flange 40 of the valve member. When the lever member I00 is in the position shown in Figs. 3 and '7, the leaf spring H0 is held under tension and when the lever member I00 pivots slightlyin a counterclockwise direction the force of the leaf spring holds the valve seated to prevent leakage of fuel through the valve port. As the lever member I00 moves in a counterclockwise direction the tension force on the leaf spring H0 is reduced and when the said force becomes less than theforceexerted by the coil spring 43, the spring 40 will act to move the valve member to open position. The lever arm I09 is preferably formed havinga downwardly extending reenforcing flange II! that extends longitudinally of the lever arm andjoins the lever arm I00. Adlacent its free end the lever arm I09 is provided with an extended portion or flange Ill having a horiother end abutting the slidable collar 00. The zontal flat or table portion Ill, see Figs. 9 and I toward each other.

10, for a purpose to be hereinafter described. The flange portion I I3 is integral with the flange II2, extending from the side face of flange II2 toward the side wall 36 of the casing 30.

Pivotally supported on the shaft IOI there is a second lever member H5. The lever member H5 is formed having a pair of spaced, substantially parallel arms II6 which are integrally connected by a horizontally extending connecting portion I I1. The arms I I6 extend upwardly from the opposite ends of the connecting portion H1 and are positioned between and extend longitudinally of the spaced arms I03 and I04 of the lever member I00. The connecting portion II! is provided with a bore II3 that extends longitudinally therethrough for loosely receiving a pin I I9 that has its opposite ends secured in aligned apertures provided in the lever arms I03 and I04 adjacent their lower ends. The diameter of the bore I I8 is larger than the diameter of the pin I I9 to provide for slight relative movement, or a lost motion connection between the lever members I00 and H5.

The lever member II5 has an integral lever arm I20 that joins the connecting portion H1 and the lever arm II6 that is disposed toward the cover of the casing 30. The lever arm I20 extends upwardly from the connecting portion H1 and toward the valve stem 29, and has a substantially horizontally extending arm portion I2I that extends over the upper end of the valve stem for engagement with the abutment flange 40 thereof. The arm portion I2I extends in spaced, substantially parallel relation with the lever arm I09 and is positioned to engage the flange 40 at one side of the longitudinal axis of stem 29 and adjacent the cover 35. The lever member I I5 has another and upwardly extending arm portion I22 that is integral with and joins arm I20 at the junction point of the horizontally extending arm portion I2I. The arm portion I22 has an upper end portion I23 oifset inwardly, or toward side wall 36, the offset portion being disposed substantially midway between the lever arms I03 and I04 and extending substantially parallel therewith. In the opposite faces of the oifset portion I23 adjacent its upper end, are provided substantially conical recesses or sockets I25. The lever memher I I5 has laterally spaced, substantially parallel arms I26 which are secured one to each of the lever arms- I03, I04 and extend upwardly therefrom. The arms I26 are secured to the arms I03, I04 by hinge members I21 in the form of resilient metal plates, preferably of phosphorous bronze, riveted or otherwise secured to the arms I03, I04 and arms I26, such thatthe arms I26 constitute flexible portions of the lever member H5. The free ends of the flexible arms I23 are provided with inwardly facing, substantially conical recesses or sockets I28, the recesses I28 and I .being located preferably substantially in the same vertical plane, extending transverse of lever member I00. The levers I00 and H5 are connectedby thrust members I29, preferably rods or pins, which terminate at their opposite ends in conical points I30 seating in the pairs of sockets I25 and I23.- The pins I29 are held in position in engagement with the sockets I25 and I23, by the resilience of the hinge members I21 and by a ten-' sion spring I3I secured at its opposite ends to the flexible lever arms I26, urging the flexible arms of the helical coil type terminating at its ends in hooks I 32 engaged in an aperture in the flexible arms I26, the spring being held under tension between the portions I26 so that said portions are The spring I3I is preferably under tension but permitting them to move outwardly with respect to the lever arms I03 and I04 'oi lever member I00.

The bottom wall 32 of the casing 30'is preferably iormed having a boss I34 disposed adjacent end wall 33 and substantially midway between side walls and 36, the boss I34 being provided with a threaded bore I35 therethrough opening into the casing through the bottom wall 32. The axis of bore I35 is preferably angularly disposed relative to the bottom wall 32 of the casing 30 and extends upwardly toward the lever member II5. Screw threaded in bore I 35 there is an adjustable stop member in the form of a screw I36 that projects into the casing 30 and has its inner end disposed for abutment with the laterally extending connecting portion II1 of the lever member H5. The stop member I33 limits movement of the lever member H5 in a clockwise direction, as seen in Fig. 7, but does not limit movement of the lever member I00 by reason of the lost motion connection between the lever members I00 and Carried by the lever arm I2I, adjacent its free end, there is an adjustable abutment or bearing member in the form of a pin I 31 which is arranged to engage or bear against the upper face of the flange of the valve member 24, see Figs. 9 and 11. The lever arm I2I is formed having an enlarged portion I33 adjacent its free end for housing the adjustable bearing pin I31 and associated parts. The enlarged portion I33 is provided with a vertically extending bore I39 that opens through the upper end of the enlarged portion I33 and has a reduced bore portion I 40 that opens through the underside of the enlarged portion I33, the reduced portion I 40 providing an upwardly facing annular shoulder or seating surface I M. The bearing pin I31 has an enlarged portion or head I42 that positions in, and is slidably engageable with, the wall of bore I39 and has a reduced portion I43 that extends through, and is slidably engageable with, the reduced bore I40. The downwardly facing annular shoulder formed between the head I42 and reduced portion I43 is adapted to seat on the upwardly facing annular shoulder I4I to limit downward movement of the pin I31. A lower end portion of the pin I31 projects below the underside of the enlarged portion I33 and is preferably rounded, as at I45, to reduce' friction between the end of the pin and the flange 40 of the valve member. Extending laterally through the enlarged portion I33 of lever arm I2I there is a bore I46 that intersects bore I39, and in the bore I46 there is a rotatable shaft 141. The rotatable shaft I41 is formed adjacent its inner end with an annular relieved portion I43 having a cam contour or face that overlies the upper end or head I42 of the bearing pin I 31. The head of the bearing pin I31 engages the cam face I43 which acts as a stop for the pin, and it will be seen that by rotating the shaft I41 the vertical position of the pin I31 relative to the arm I2I can be changed. The enlarged portion I38 of the lever arm I2I is formed having a vertically extending boss having a bore I 50 therethrough, that intersects the laterally extending bore I at right angles thereto and at a point adjacent groove I52 in the shaft I41 to limit longitudinal movement of the-shaft. A coil spring I53 is disposed in bore I and has one end abutment ,with the upper end of the plunger II and its other end, or upper end, in abutment with the lower end of a set screw I54, the coil spring being held under compression by the set screw and ms- 5 ing the plunger I5I downwardly into engagement with the shaft I61. The outer end of the shaft I41 preferably has a head I55 which is disposed toward the casing cover 35 and may be provided with a slot to receive a screw driver, or other tool 10 for rotating shaft I61 to adjust bearing pin I31. Preferably a fixed dial plate I56 and cooperative movable pointer I51 are provided for indicating the adjustment or setting of the adjustable bearing pin I31. The dial plate I56 may be held against the outer face of the enlarged portion I36 with the face of the dial being disposed toward the casing cover 35. The dial plate I56 has an aperture for receiving the shaft I61 and is held between the outer side faceof the enlarged por- 26 tion I38 and the pointer means I51 by means of the coil spring I53 which urges the shaft I61 inwardly. The pointer means I51 is fixed for rotation with the shaft I61 and is disposed between the-head I55 of the shaft and the dial plate I56. 25 The casing 36 is formed having a wall portion I66 at its open side, or adjacent the cover 35, the wall portion I66 joining thetop wall 6| and end wall 36 and being substantially parallel with the side or rear wall 36. In the wall portion I66 66 is secured one end of a stub shaft IIiI that extends within and across the casing 36 adjacent to, and substantially parallel with, the end wall 36. A lever member I62 is pivotally supported on the stub shaft I6I, the lever I62 being of the bell crank type, in the present instance, having lever arms I63 and I66. The lever arm I63 ex- I tends longitudinally o the casing 86 and has an end portion which overlies and is adapted to engage or bear against the upper face of the to lever arm I69 of the lever member H5. The lever I62 is pivoted to the stub shaft I6! at a point substantially midway between the side walls and the top and bottom walls of the casing 36.

A coil spring I65 acting through the bell crank 45 lever I62 is adapted to close or seat the valve member in the event that the pilot light burner 5 becomes extinguished. In the top wall 3| of the casing 36, adjacent the end wall 36, there is provided an aperture closed by a closure plug 6.

' 50 the closure plug I66 preferably having a lower end portion I61 projecting into the casing 66. One end, or upper end of the coil spring I65 surrounds the lower end portion I61 of the closure plug I66, the end portion L6] serving to hold the 55 upper end of the spring against lateral movement. Seated in the other, or lower end of the spring I65 there is an abutment member I68 which has a central aperture for receiving a thrust member I66. The thrust member I66 prefeo erably has a tapered or conically formed end I16 that is adapted to seat in a conical recess I1I provided in the upper face of the lever arm I66 ad-, jacent the pivot point of the bell crank lever I62. The thrust member I69 preferably includes a stem 5 portion which extends centrally and longitudinally through the coil spring I65 and has its free end extending into a centrally bored recess I16 in the closure plug I66. The lever arm I64 of the bell crank lever I62 extends downwardly and toward 70 the adjacent end wall; 84 of the casing 36.

Mounted on the casing 66 and secured to the end wall 84, externally of the casing, there is provided a power element, designated in general by the numeral I15, which acts to prevent the 75 spring I65 from closing the valve member 24 as long as the pilot light burner 5 remains lighted. The power element I15 includes a tubular or cupshaped casing I16 having one end open and disposed toward the end wall 34 of the main casing 36, the end wall 34 having an opening I11 therethrough which is closed by the power element casing I16. Preferably the power element casing I16 has an outturned annular flange I18 at its open end which seats against the outer face of the end wall 34 and is provided with apertures for receiving screws I16 for rigidly securing the power element casing I16 to the main casing 36. Fitting or telescoping within the power element casing I16, and located adjacent its open end, there is a plate member I86 which preferably has an "annular flange I6I whose outer face engages the inner wall of the casing I16. The,plate member I66 is to be secured and hermetically sealed to the inner wall surface of the casing I16 by solder, or other suitable means, so that there will be a fluid-tight joint between the outer face of the annular flange I8I and the inner wall of the casing I16. The plate member I86 is provided with a centrally disposed aperture, and secured and hermetically sealed to a border portion around the aperture is one end of a metallic bellows member I62. The bellows member I82 is disposed within the casing I16 and has its other, or free end closed by an end wall or plate member I83 which is secured and hermetically sealed to the free end of the bellows member. Secured to, and carried by the movable end wall I63 of the bellows member I62 there is a thrust member I66 which extends centrally through the bellows and projects into the main casing 66. The free or inner end of the thrust member I86 is preferably pointed or conical in form, as at I85, for seating in a conical recess provided in the arm I66 of the bell cranklever I62.

The bellows member I82 and easing I16 cooperate to provide an expansible pressure chamber I86, and communicating with theichamber I86 is one end of a tube or conduit I81 which may be secured in and to the side wall of the casing I16 in any suitable fluid-tight manner. The other end of the tube I81 is connected to a temperature responsive element or bulb I88 which is disposed in heat transfer relation with the.

flame of the pilot light burner 5, Figs. 1 and 3. In' the present instance, the temperature responsive element or bulb I88 is in the form of a tube or conduit which is coiled or wrapped around a shield member I66 that overlies the pilot burner flame. The temperature responsive element 686, pressure chamber I86, and connecting conduit I81 contain a quantity of fluid, such asaniline,

that is expansible and contractible in response to changes in temperature. When the pilot light burner 5 is lighted, the expansible-contractible fluid will be expanded and will exert its force against the movable end wall-of the bellows member I82. The bellows member I62 will be compressed, transmitting the force of the expanded fluid through the thrust member I84 to pivot the bell crank lever I62 in a clockwise direction, to the position shown in dotted lines in Fig. 7.- The force exerted by the power element I15 when the pilot light is lighted, is greater than the force exerted by the spring I so that the spring is compressedand the lever arm I68 is held out of engagement with the valve member 24 during normal operation of the system, or when the pilot light is lighted.

Integral with "the side wall .86 of the main casing 36, and disposedadjacent the end wall 34, there is an externally and laterally extending boss I90, and through the boss I and side wall 36 there is a bore in which a shaft I9I is journaled for rotation, see Fig. 9. 'The shaft I9I is disposed with its axis of rotation aligned with stub shaft I6I and substantially parallel with the casing end wall 34, and has an inner end portion that projects into the casing 30. A-lever member I92 is disposed in the casing 30 and is secured at one end to the shaft I9I for movement therewith. The lever member I92 extends longitudinally of the casing 30 and has a portion of its other, or free end provided with a downward extending toe or boss overlying and adapted to bear on the table portion II3 of flange I I3 of the lever arm I09 to actuate the valve member 24. The shaft I 9I has an end portion that projects externally of the casing 30 and boss I90 and is provided with a square shank I93, see Fig. 5, which receives and has secured thereon the polygonally apertured end of a lever member I94 that pivots or moves with the shaft I9 I. Pivotally connected to the free end of the lever member I94 is one end of a connecting link, or rod I95, see Fig. 1, the other end of the connecting link being connected to the inlet draft damper I2 of the furnace I. When the lever I94 pivots in a counterclockwise direction, as seen in Fig. l, the damper I2 is closed and conversely, when the lever pivots in a clockwise direction the damper I2 swings downward by gravity to open position.

Mounted on the casing 30 there is a heat motor I95 that actuates the valve member 24 through operation of the lever member I92, the heat motor being controlled by the room thermostat I5. When the room thermostat is dissatisfied the heat motor acts to permit the valve 24 to be moved to open position by the coil spring 43, and when the thermostat becomes satisfied the heat motor acts to seat the valve. The heat motor, see Fig. 5, includes a casing I96 that is preferably a casting having a top wall I91, bottom wall I98, side walls I99, 200, and end walls MI, 202. The side wall I99 is disposed toward and adjacent the side wall 36 of the main casing 30, and the two casings may be secured together by screws 203, or by other suitable means. The heat motor includes a power element which in turn includes a casing 204 that telescopes or flts into the casing I96.- The casing 204 has one end, or its outer end, closed by an end wall 205 that is disposed substantially flush with the end wall 202 of casing I 96, the end wall 202 being provided with an opening through which the casing 204 is positioned within casing I96? Theother, or inner end of the casing 204 is open and terminatessubstantially midway between the end walls of thecasing I96, and disposed within the casing 204.

adjacent its open end, there is a plate member 206 that extends'substantially transverse to the side wall of casing 204. The plate member 206 is formed having an annular inturned flange 201 that conforms in contour and positions with its outer periphery flat against the inner side wall of the power element casing 204. The flange 201 may be secured to the inner wall surface of casing 204 by solder, or by other suitable means, to provide a fluid-tight joint therebetween. The plate member 206 is provided with a, centrally disposed aperture therethrough and secured and hermetically sealed to a border portion of the plate, around its aperture, is one end of a bellows member 208. The bellows member 208 extends longitudinally through the casing 204 having its other, or free end disposed toward the closed end or casing 204, and secured and hermetically sealed to the free end of the bellows is a movable wall or plate member 209. The bellows 208 and casing 204 cooperate to provide an expansiblechamber 2I0.

Secured to the end wall 202 of casing I96 there is an L-shaped bracket 2 that has a verticallyextending plate portion or leg 2I2 overlying and closing the opening in end wall 202. The bracket 2" may be secured to the casing I96 by screws, or by other suitable means. The inner face of the plate portion or leg 2I2 abuts the end. wall 205 of casing 204 and is preferably secured thereto by solder, or by other suitable means, to prevent inward movement of the casing 204. The L- shaped bracket 2 has a horizontally and outwardly extending plate portion or leg 2I3 at its upper end, and secured to and depending from the underside of the horizontal leg 2I3 there is a tubular casing 2 I4. The upper end of the tubular casing 2I4 is open and has an annular flange 2I5 that seats against the underside of the horizontal bracket, or leg 2I3. The annular flange 2I 5 may be provided with apertures to receive screws for rigidly securing the tubular casing 2I4 to the bracket 2I I. Disposedwithin the casing 2I4 and extending longitudinally thereof, is a bulb element 2I6 which is connected in communication with the expansible chamber 2I0 by a conduit or tube 2I'I. A slot 2| 8 is provided in the side wall of the bulb element casing 2I4, extending longitudinally thereof, through which the tube 2I'I projects, externally of the casing, for connection in. the end wall 205 of casing 204. In the bulb 2I6, expansible chamber 2I0, and connecting tube 2" there is contained a quantity of fluid that is expansible and contractible in accordance with changes in its heat content, such as methyl chloride.

Surrounding or wrapped around the bulb ele- .ment 2I2, adjacent the upper end thereof, is a coil of wire 2I9 having a high resistance of flow of current therethrough so as to generate heat. Disposed within the casing 2I4 and surrounding the coil of resistance wire 2I9 there is preferably provided a polished metallic reflector 2I9 for reflecting the heat given oil by the resistance coil and directing the heat toward the temperature responsive bulb 2I6. The heat generated by current passing through the resistance coil 2I9 heats the fluid in bulb 2 I6 and the fluid expands, exerting its force to compress the bellows 208. Mounted on the horizontal leg 2 I3 of the bracket H I there is a block of electric insulating material 220 which may be formed of Bakelite, or other suitable material, and which may be secured to' the leg 2I3 by screws 22I, or by other suitable means. Secured in the insulating block 220 there is a pair of terminal posts 222 to which the ends of the resistance wire 2 I9 are attached and may be secured by solder, or by other suitable attaching means. The terminal posts each have a binding post in the form of a screw 223. Overlying the block 220 and enclosing the terminal posts 222 there is a conduit outlet box 224 having an outlet opening 224. i

The movable end wall 209 of the bellows 208 is provided with a centrally disposed aperture for receiving an end portion of a tubular shaped, or longitudinally bored collar 225 thats secured thereto. The collar 225 has a shank portion that projects into the bellows 208 and has an external annular flange 228 that seats against the inner face of the movable wall 209. The collar 225 may -fiange 228 of the collar 225.

proof manner by peening over the end portion of the collar to tightly clamp the movable end wall 209 between the flange 228 and the peened over portion. Secured and sealed in the bore of the collar 225 is one end of a filler tube 230 through which the expansible-contractible fluid is introduced into the pressure chamber 2I0. After the fluid has been introduced into the pressure chamber the tube 230 is severed and the severed end sealed by solder, or by other suitable sealing means.

Disposed within the casing I96 and extending longitudinally thereof is a thrust member which includes a rigid tube 232 having an end portion extending centrally through the bellows 208 and surrounding the filler tube 230 and collar 225. An inner end portion of the rigid tube 232 is internally threaded to receive an externally threaded tubular abutment member 233 that abuts the The diameter of the bore through the tubular abutment member 233 is larger than the diameter of the shank 226 of the collar 225 to permit lateral movement,

or canting of the rigid tubular member, for a purpose to be hereinafter described. The other, or outer end of the tubular member 232 is disposed adjacent the end wall 20I of casing I96, and carried by the tubular member at its outer end there is a connecting member or link 235. The tubular member 232 is formed at its outer end having an end wall provided with a centrally disposed aperture through which the connecting member 235 extends, the connecting member having an external annular flange or head 236 positioned in the tubular member 232 and adapted to abut the end wall thereof. The connecting member 235 projects externally of the tubular member 232 and its outer end is bifurcated to receive an upstanding arm portion 231 of the lever member I94. The lever member I94 and the bifurcated end portion of the connecting member 235 are provided with aligned apertures to receive a pivot pin for pivotally connecting the lever member I94 and the connecting member 235. Disposed within the tubular member 232 and extending longitudinally thereof there is a coil spring 230 that has one end in abutment with the head 236 of the connecting member 235, and its other end in abutment with the abutment member 233 of the tubular member 232. The coil spring 238 is under compression and acts to maintain the head 236 of the connecting member 235 in engagement with the end wall of the tubular member 232. The connecting member 235 is movable relative to the rigid tube 232 so that in the event the lever I94 is manually operated when the bellows 208 is under pressure, the bellows will not. be injured.

Disposed within the casing I96 adjacent the end wall 20I thereof, there is a holding means that opposes the heat motor and acts to seat and hold the valve member seated, and this holding means includes a tubular member 240.

The tubular member 240 has an outer end portion 2 which is preferably conical in shape and projects externally of the casing I96 through anopening 242 in the end wall 20! of the casing. The conical shaped end portion 24I of the tubular member 240 has an opening in its underside through which the upwardly extending arm portion 231 of lever I94 projects into the tubular member. The arm portion 231 has an extended portion 243 that extends outwardly and toward the apex of the conical shaped end portion 24I,

' the end of the extended portion 243 bearing against a seat member 244 that is secured in the conical portion substantially at the apex thereof. Surrounding the tubular member 240 within the casing I96 there is a coil spring 245 that has. one end abutting wall 20I and its other end abutting an external annular flange 246 formed on the inner end of the tubular member 240. The coil spring 245 is under compression and acts to move the tubular member 240 inwardly to pivot the leverarm I94 in a clockwise direction, as seen in Fig, 5. Pivotal movement of the lever I94 in a clockwise direction rotates shaft I9I and the lever I92 untilv the valve member 24 is seated, and the spring 235 holds the valve member seated until overcome by the heat motor.

When the heating coil 2I9 of the heat motor is energized the fluid in bulb 2I6 will be heated and will expand, with accompanying increase in pressure acting to compress the bellows 208. When the force exerted by the expanded fluid acting on the bellows 208 overcomes the opposing force exerted by the spring 205, the bellows will compress and move the thrust member to rotate the lever I 9d in a counterclockwise direction, which will move lever I92 away from the valve member 24 permitting spring to move the valve to open position. The lever member I94 is formed having a lateral flange 241 at its lower edge for abutment with an external boss 240 formed on the side wall 30 of the main casing 30 to limit pivotal movement of lever I99 when the lever is actuated by the heat motor.

Carried by the lever arm I94 is the tilt or pendulum switch I6. The tilt switch I6 is housed in a casing 250 that is preferably a casting of rectangular shape having a top wall 25I, bottom wall 252, side walls 253, 254, and end walls 255, 256. The side wall 253 is formed by a removable closure member or cover in the form of a plate that may be secured to the casing 250 by 2 screws, or by other suitable means. The casing 250 is formed having integral and oppositely extending external ears or flanges 251 and 258 that extend from opposite end walls of the casing and are flush with the side wall 254. The flanges 251 and 258 lie flat against the side of lever I94 and are provided with apertures for receiving screws 259, 260 which thread into the lever arm I94 to rigidly secure the casing 250 to the lever. The aperture in the flange 251 is preferably in the form of a slot, as shown, so that the position of the casing 250 relative to the lever arm I94 can be adjusted. Integral with the side wall 254, adjacent the top wall 25I, there is an external tubular boss 260 Fixedly secured in the boss 260 and projecting into the casing 250, there is a supporting member 26I in the form of a rod, or pin. The supporting pin 26 I extends across the casing 250 to the side wall 253, and intermediate its endsand within the casing 250, the pin 26I is provided with an upwardly directed edge 262.

Disposed within the casing 250 and extending longitudinally thereof there is an oscillatory member or pendulum 263 that is supported for swinging movement from one position to another to make and break circuit in accordance with movement of lever arm I94. The oscillatory member 263 is pivotally supported at its upper end on the pin 26 I and depends therefrom. The

oscillatory member 263 is provided with an-aperproviding a V-shaped recess that extends along the face of the bore, from end to end, and seats on the upwardly directed bearing edge ,262 of the pin 26I.

Disposed within the casing 250 there is a jumper strip 266 in the form of an L-shaped plate member that has a vertically extending portion or leg which is positioned flat against the inner suriace of end wall 256. The L-shaped jumper strip 266 has a horizontal leg portion 261 that extends from end wall 256 toward end wall 255 beneath the lower end of the oscillatory member 263. The jumper strip 266 may be secured to the wall 256 by a screw 268, and clamped or secured under the head of the screw 268, externally of the casing 250, there is another jumper strip 269 to which one end of a jumper wire 210 is connected and may be secured, such as by solder. Adjustably screw threaded in the side wall 256 and through a threaded aperture in the vertical leg of the jumper strip 266 there is a contact member 2" that has an inner end portion projecting into the casing 250. Carried by the oscillator: member 263 there is a metallic contact strip 212 that extends longitudinally of the member 263 and is disposed toward, or faces, the end wall 256 of the casing 250. The contact strip 212 may be secured at its upper end to the member 263 by screws 213, or by other suitable means. Carried by the strip 212 adjacent its lower end, there is a contact member 215 which is positioned to engage with the inner end of contact member 21I. When the valve member 24 is being held in closed position by the spring 245, as shown in the drawings, the contactmember 215 carried by the oscillatory member 263 is in engagement with the contact 21 I. To insure positive engagement of the tilt switch contacts there is preferably provided a permanent magnet 216 that may be carried by the oscillatory pendulum member 263. The magnet 216 may be adjustably screw threaded into a threaded bore, in and adjacent the lower end of the pendulum member 263, and may have one end disposed toward and adjacent the vertical leg of the L-shaped jumper strip 266. When the power element acts to open the valve member, and in doing so pivots lever I94, the oscillatory member 263 remains in its vertical position while the casing 250 tilts and contact member 21I, carried by the casing, moves away from contact 215 to break circuit. Threaded into the outer end of the supporting member or pin 26I there is a binding post in the form of a screw 216 on the head of which is secured one end of a jumper wire 211. Secured to the end wall 34 of the main casing 30 there is an L-shaped bracket 218 that has a horizontally disposed portion or leg 219 on which is mounted a block or pad of electric insulating material 289, such as Bakelite. A pair of vertically extending, spaced terminal posts RI, 282 are mounted on the bracket 218 and have their lower ends secured in and to the electric insulating material 280. The other ends of the jumper wires 210 and 211 are respectively connected to the terminal posts 28 I, 282.

The operation of the power element 52 and associated mechanism that actuates the valve member 24 in response to furnace bonnet temperature is as follows: As previously mentioned, when the room thermostat I5 becomes dissatisfied the heat motor is energized and when the force exerted by the heat motor plus the force of valve spring 43 and the lever-moving component of force of spring I3I slightly exceeds the opposing force of the spring 245, then the lever arm I92 will be lifted or turned counter-clockwise, facing Fig. '1,

so that the spring 43, if not opposed by arm I63 and rod 65, can move the valve toward jopenposition. When the force exerted bythe'spring 245 is overcome, the initial movementoi lever, I 92 will permit the coil spring I3I to move theiouter ends of pins I29 toward each other thereby. forcing the lever member I00 in a counterclockwise,direction, as seen in Figs. 3 and 7, so that the lever arm I09 will move upward with the arm I92 and will soon move out of direct engagement with the valve member. For a slight movementof the lever member I00, the tension leaf spring 4| I0 exertsa greater force than the valve opening coil spring I3, with the result that, the valve member is held seated during the initial movement of the lever member I00. .However, initial pivotalmovement of the lever member I00 and itsarm I09 in a counterclockwise direction resulting from the force exerted by spring I3I, causes an increase in the component of force of the spring,I3I acting through pins I29 to pivot the lever. As, the active component of the spring I3I increases with each increment of movement of lever I00, it will be apparent that the initial force required to overcome spring 245 is suddenly increased so that lever member I00 is pivoted and arm :I09 is lifted with a snap action. Lever arm I09 being thus moved quickly away from holding engagement with the valve member and thereby releasing the inherent force exerted by the resilience of the leaf spring IIO, the valve member is opened with a snap action by the quickly unleashed potential force of the compressed coil spring 43.; Thespring I3I yieldably holds the lever members I00 and H5 for movement in unison, and urges the lever members to pivot in opposite directions, the movement of-member II5 howeverbeing limited tostop screw I36 and relative movementof. the lever members-being limited by the pin 1 I9:.which acts asa stop by engagement with :the wall of aperture IIB. When the movement of. lever member I00 is limited by pin I I9, then spring I3I will be inefiective to continue the valve opening movement, which will howeverbe' continued by i the valve spring 43 as the force of the expanding fluid in the heat motor unaided bythe force of spring I3I becomes equal to and overcomes spring 245. As the furnace temperature" increases by reason of the operation of the burner supplied by valve I1, the expansible fluid of thepower element 52 exerts an increasing force actingsthrough the thrust member 65 and the lever members I00 and I I5 to move the valve member toward closed position. The temperature responsive element, through the lever members I00 and I I5, throttles the valve member in accordance with changes in furnace bonnet temperature, and it is to be-understood that during the throttling of the valve'memher only the lever member H5 is in engagement with the valve member, the bearing point of'lever member I00 being slightly spaced from andabove the bearing flange 40 due to the priordescribed relative movement of members I00 and i I5. During the throttling action the levers I00 and IE5 pivot in unison by reason of the holdingspring I3I, but if the bonnet temperature continues to rise above a predetermined desired degree; the lever member II5 will be prevented from=further pivotal movement in a valve closing direction by the stop member I36. The furnace bonnettemperature at which the lever member- H5 will engage its stop is determined by the-adjustment of the spring abutment member 12. When the lever member I I5 engages its stop member I36 the valve member 20 may or may not be seated, and the t9 efiective flow capacity of the valve port 22 will depend upon the adjustment of the adjustable thrust pin or bearing member I31 of lever H5. If the adjustable bearing niember I31 is in the position shown in Figs. 11 and 12, with pointer I51 as in Fig. 3 wherein member I31 is being held in its lowermost or extended position, the valve member will be slowly throttled closed by the power element 52 and will be seated when the lever member I I5 is in engagement with its stop. If the adjustable bearing member I31 is set at the other extreme, or uppermost position with pointer I51 directed toward wall 33,. the valve member will not be seated when the lever member engages its stop member I36. This last mentioned position of the valve member 24 may be termed the minimum throttle position of the valve since the range of throttle is increased as the position of the pointer I51 is moved clockwise and toward the right, facing Fig. 3. That is to say, by moving the bearing member adjustment means so that the pointer I51 moves to the right, Fig. 3, the valve member will be closer to its seat when the lever member II5 engages its stop. If for some reason the bonnet temperature continues to increase after the valve has been i moved toward closed position, such that the lever member I I5 is in engagement with its stop I36, the power element will act to overcome the opposing force created by the holding spring I3I. When the force of the power element slightly exceeds the component force of the spring I3I the lever member I00 will begin to pivot in a clockwise direction, as seen in Figs. 3 and '7, and as the outer ends of the thrust pins I29 move toward alignment with their inner ends, the component force of spring I3I rapidly decreases with the result that the lever member I00 is pivoted with a snap action. The lever arm I09 moving with the lever I00 engages with the flange 40 of the valve member and thus the valve is closed, or seated with a snap action. It is to be understood that the valve is actuated with a snap action only when the bearing member I31 is set in other than its lowermost or fully extended position. When the furnace bonnet temperature decreases to a predetermined temperature the spring I3I will pivot lever member I IS in a counterclockwise direction, as seen in Figs. 3 and 7, and will permit the valve to be opened by the spring 43 with a snap action.

Referring now to my damper and automatic damped actuating means shown in Figs. 1, 14 and 15, this apparatus includes a pipe or flue section 285 in which a rotatable damper 286 is disposed for controlling flow therethroug h, the flue section being interposed in the furnace stack 8. The flue section 285 is preferably a casting having an external and vertically extending flange 281 in the form of a plate providing a mounting on which the damper actuating mechanism and associated parts are mounted as a unitary structure. A supporting member or terminal board 288 is mounted to, and flat against the vertically extending flange 281 and this terminal board may be constructed of Bakelite, or other suitable electric insulating material. The damper actuating mechanism includes a heat motor that has a supporting member, preferably an open-ended casing 289 that has one end abutting and closed by the terminal board 288. The other, or opposite end of the casing 289 maybe closed by a removable closure member or cover in the form of a plate 290 that may be secured to the casing by screws, or by other suitable attaching means. The casing 289 may be provided with ears or flanges 29I having apertures for receiving screws that may extend through apertures in the terminal board 288 and thread into the flange 281 to tightly clamp and rigidly secure the flue, board, and casing together.

The flue section 285 is preferably formed having oppositely and outwardly extending tubular bosses 292 and 299 that are integral with the side wall of the flue section and are disposed with their axes in substantially horizontal alignment. Screw threaded into the bosses 292, 293 there are preferably provided removable tubular bearing members 294 and 295 respectively. The bearing member 295 is in alignment with, and in the present instance has an outer end portion that projects into an aperture 296 through the flange 281 of the flue section 285. Journaled for rotation in the bearing member 295 there is a stub shaft 291 which projects into and transverse of the flue section 285. Journaled for rotation in the other bearing member 294 there is a stub shaft 298 that has an inner end portion projecting partway into the flue section 285 in axial alignment with the shaft 291. Secured to the inner end portion of the shafts 291, 298 is the damper 286 which may be.secured thereto by rivets 299, or by other suitable means. The stub shaft 298 projects externally of the flue section, and beyond the outer end of the tubular boss 290, and to its outer end there is preferably secured a handle 300 for manually actuating the damper 286.

The heat motor casing 289 is preferably a casting having a top wall 302, bottom wall 303, and side walls 304 and 305. The casing 299 is formed having two integral and externally extending tubular bosses 306 and 301 that are oppositely disposed and open into the casing through the side walls 304 and 305, respectively, and adjacent the top wall 302. An L-shaped bracket 308 is secured to the outer end of the tubular boss 306, the L-shaped bracket having a vertically extending plate portion or leg 3I0 that overlies and closes the outer end of the boss 306, and having an outwardly extending horizontal plate portion or leg 3| I. Carried by the L-shaped bracket, as a unitary structure, is the heat motor which includes a power element that in turn includes a tubular casing 3I2. The tubular casing 3I2 positions in the tubular boss 306 and has its inner end projecting into the casing 289, the inner end wall, as at 3I3, having a centrally disposed aperture therethrough. The other, or outer end of the power element casing 3I2 is open, and a portion of its side wall at said open end, projects and is secured in a continuous recess provided in the inner face of the vertical leg 3I0 that overlies the outer end of the tubular boss 306. The power element casing 3| 2 may be secured to the vertical leg 3I0 by solder, or by other suitable means for sealing in a fluid-tight manner.

Disposed within the power element casing 3I2 there is a metallic bellows member 3I4 that has one end secured and hermetically sealed to a border portion of the end wall 3I3, around the aperture therethrough. The other end of the bellows 3| 4 is secured and hermetically sealed to a movable end wall, or plate member 3I5. The bellows member 3I4, its casing 3I2, and the-vertical leg 3I0 of the L-shaped bracket 308 cooperate to provide an expansible pressure chamber 3I6. Secured to the underside of the horizontally extending leg 3 of bracket 308 there is a tubular casing 8 that depends therefrom. The upper end of the casing 3!! is open and has an outturned annular flange that may be provided with apertures for receiving screws for rigidly securing the casing to the bracket 388. Disposed within the casing 3!! there is a temperature responsive element or bulb 3|8 that extends longitudinally of the. casing, in the present instance. A tube or conduit 3!!! prcvidescommunication between the interior of the bulb 3!8 and the expansible chamber 3!6. One end of the tube 3!9 may be secured to and in the lower end of the bulb element 3l8, and the other end of the tube may be secured to and in the vertical leg 3!8 of the L-shaped bracket 388. The bulb casing 3 l! is provided with a slot 328 extending longitudinally thereof,

through which the tube 3!!! projects externally I of the casing. The expansible chamber 3l6, tube 3l3, and bulb 3!!! contain a temperature responsive, expansible contractible fluid which may be methyl chloride.

Surrounding or wrapped around an upper end portion of the bulb 3!8 there is a coil of wire 32! that has a high resistance to passage of current therethrough so as to generate heat to heat the fluid in the bulb. Disposed within the bulb casing 3!! and surrounding the resistance coil 32! there is preferably provided a shield or reflector member 323 for reflecting the heat given off by the resistance coil 32!, and directing the heat toward the bulb 3!8. Mounted on, and secured to the'top face of the horizontal leg 3!! of the bracket 388, there is a block or pad of electric insulating material 324 which maybe Bakelite. A'

pair of terminal posts 325 have their ends secured to and in the insulating material and attached, one to each terminal post, are the ends of the coil of resistance wire 32!.

Secured in and projecting centrally through the movable wall 3 !5 of the bellows 3 I4 there is a collar 326. The collar 326 is provided with a centralbore longitudinally thereof, in which is inserted and secured one end of a filler tube 32'! through which the expansible-contractible fluid is introduced into the power element. The collar 326 is formed having a shank portion that projects into the bellows 314, and sleeve-fitted over the shank portion there is a, loosely disposed for screw threading into one end, of a rigid tube 338. The tube 338 extends centrally through the bellows 3! 4 and projects through the inner end wall 3!3 of the bellows casing 3!2 and into the casing 289. Carried by the tube 338, at its inner end, there is a thrust member 33! that has a head within, and adapted to abut the innner end wall of the tube, and has a shankportion that projects externally of the tube and into the casing 289. The thrust member 33! is. slidablelongitudinally of the tube 338 and is yieldably held against the end wall of the tube by a coil spring 332. The coil spring 332 is disposed within the tube 338, having one end abutting the abutment member 328 and the other end abutting the innet end of the head of thrust member 33!. The coil spring 332 is under compression and is adapted to transmit movement of the bellows 3!4 to the thrust member 33!, but in the event the damper 286 is manually operated against the force of the power element, the spring yields to prevent rupture of the bellows.

The tubular boss 38'! of the casing 289 is preferably internally threaded for receiving an externally threaded closure plug 334. The closure plug 334 is provided with an axially extending ably supported in the bore 335 there is a thrust member 336. The outer end of, the thrust member 336 is preferably provided with an external annular flange or head 33!, for abutment with the end wall of the closure plug 334 to limit inward movement of the thrust member 336. The thrust member 336 projects into the casing 289, preferably in axial alignment with the thrust member 33!, and the inner end of the thrust member 336 is preferably pointed, as at 338. Adjacent its inner end the thrust member 336 is provided with an external and outwardly facing shoulder against which an abutment member 348 is adapted to seat, the abutment member 348 having a centrally disposed aperture for receiving the thrust member 336 and being slidably movable longitudinally thereof. The abutment member 348 is cup-shaped, in the present instance, and has an extemai annular flange 34!. Surrounding the thrust member 336 there is a coil spring 342 that has one end in abutment with the external annular flange 34! of the abutment member 348, and has its other, or outer end in abutment with the inner end of the closure plug 334. The spring 342 is under compression acting to urge the thrust member 336 inwardly. Integral with and depending from the underside of the top wall 382 of casing 289 there are a pair of spaced arms or bosses 344 that are positioned above and between the inner ends of the thrust members 33! and 336. The arms 344 are provided with aligned apertures for receiving'a pivot pin or shaft 345 that extends substantially transverse to the longitudinal axes of the thrust members. -A lever member 346 is pivotally supported at one end on the shaft 345 and depends therefrom, between the opposed pointed ends of the thrust members 33! and 336. The lever member 346 is preferably in the form of a plate, and preferably has side reenforcing flanges 348 longitudinally thereof that are provided adjacent their upper ends with apertures for receiving the shaft 345 to pivotally support the lever 346. As shown in Fig. 14, the lever member and one of its side flanges have cut-out portions to provide clearance for parts to be hereinafter described. Rigidly secured in and to the lever member 346, adjacent and beneath the shaft 345, there is an abutment member 349 that is preferably provided with conical recesses in opposite faces for receiving the pointed ends of the thrust members 33! and 336. I

The inner end of the damper shaft 29! preferably has a square shank 358 that projects into the casing 289, and secured to the shank there is a lever member in the form of a disc or plate 35!. Carried by-and secured to the disc 35! there is a connecting pin 352 that projects laterally from the disc and toward the cover 298 of casing 289. side flanges 348 of the lever 346, there is provided a slot 353 for receiving the pin 352. A stop member in the form of a pin 354 has one endscrew threaded into the flange 28'! of the flue section 285, and projects into the casing 289 for abutment with the disc 35! to limit; rotation of the disc in either a clockwise or counterclockwise direction. The outer edge of the rotatable disc 35! has a cut-out portion, in the present instance, providing two abutment edges 355 and 356 for abutting the stop member 354, the abutment edge 355 being adapted 'to abut the stop member to limit rotation in a clockwise direction, and the edge 856 being adapted to abut In the lower end of one of the the stop member 354 to limit rotation in a counterclockwise direction.

Disposed within the casing 289 there is a switch means that is actuated by the heat motor when the heat motor actuates the damper, and this switch means includes a pair of contact strips 351 and 353 that may be secured at their upper ends to the terminal board 288 by rivets 359, or by other suitable means. A pair of downwardly facing contact members 360 and 36I are secured to the lower ends of the contact strips 351 and 358, respectively. Secured to the square shank 350 of the shaft 291 there is a plate member 362 to which is secured one end of a contact strip, or switch arm 363 that carries two upwardly facing contact members 364 and 365 that are adapted to make contact with the contact members 360 and 36I respectively.

The operation of the damper actuating mechanism is as follows:' When the resistance coil 32I is energized, the fluid in the bulb 318 will be heated and will expand, exerting an increasing force tending to compress the bellows 3I4.

When the force exerted by the expanded fluid exceeds the opposing force exerted by the coil spring 342, the lever 346 will be pivoted in a counterclockwise direction rotating shaft 291 and opening the damper 286. Also, the switch arm 363 will be moved in a counterclockwise direction breaking contact between the movable contact members 364, 365 and their respective fixed contact members 360 and 36I. When the resistance coil 32I is deenergized the fluid in the pressure chamber 316 will contract, with accompanying decrease in force exerted against the bellows 3I4, and when the force exerted by the spring 342 exceeds the force exerted by the fluid, the lever 346 will be pivoted in a clockwise direction with the result that the damper 286 will be opened and the switch closed, which is the position of the parts shown in Figs. 13 and 14.

Provided in the face of the terminal board 288, adjacent its top edge, there is a horizontally extending groove or slot 361 in which is secured end portions of a plurality of spaced terminal posts 368, 369, 310, 31I, 312, 313, 314, 315, 316 and 311. Connecting the terminal post 3' 'and the fixed contact strip 351 there is a metallic jumper strip 318-, and connecting the terminal post 314 and the contact strip 358 there is a metallic jumper strip 319. Connectingone of the terminal posts 325 of the heat motor, and the terminal post 312 there is a jumper wire 380, and connecting the other terminal post 325 of the heat motor and the terminal post 368 there is a jumper wire 38L Each of the terminal posts 368 to 311 inclusive, may be provided with a binding post in. the form of a screw 382.

Referring now, and more particularly to Fig. 1, the devices of my control system are electrically connected as follows: The numeral 384 designates a transformer having the usual primary 385 and secondary 386. Connected to the terminals of the primary 385 are the main lead wires 381 and 388. One end of a lead wire 389 is connected to one terminal of the secondary 386, and the other end of lead Wire 389 is connected to the terminal post 316 on the terminal board 288. A lead wire 390 hasone end connected to the other of the transformer secondary terminals, and has its other end connected to the terminal post 311 on the terminal board 288. The thermostat I5 comprises, in general, a support 39I on which is mounted a temperature responsive, bi-'metal blade 392, the free end of which positions between two spaced contact members 393 and 394 mounted on the support 39I. Carried by the blade 392 adjacent its free end there is a pair of oppositely disposed contact members 395 and 396 that are adapted to make contact with the contact members 393 and 394, respectively. A jumper strip 391 connects the terminal posts 315 and 316 of the terminal board 288, and connected to the terminal post 315 is one end of a lead wire 398 that has its other end connected to the bi-metal blade 392. A lead wire 399 connects the thermostat contact membe 394 and the terminal 314 of the terminal board 288, and a lead wire 400 connects the other thermostat contact 393 and the terminal 313 of the terminal board 288. Connecting the terminals 311 and 3690f the terminal board there is a jumper wire 40l in which there is preferably provided a manually operable switch 402. Connected to one of the terminal posts 222 of the heat motor of the fuel supply control device I3, is one end of a lead wire 403 that connects at its other end to the terminal post 31I of the terminal board 288. The other terminal post 222 of the heat motor is connected to the terminal post 310 of the terminal board by a lead wire 404. A lead wire 405 has one end connected to the tilt switch terminal 282, and its other end connected to the terminal 369 of the terminal board 288, the terminal posts 369 and 310 being connected by a jumper strip401. The other terminal 28I of the tilt switch I6 is connected to the terminal 368 of the terminal board 288 by a lead wire 406. A jumper strip 408 connects the terminals 312 and 313 of the terminal board 288.

The operation of my control system for controlling the operation of a heating apparatus is as follows: The manual switch 402 on the terminal board 288 is first closed and the pilot light burner .5 lighted. The pilot light burner heats the expansible fluid in the bulb I88, the fluid expanding and acting to compress the bellows I82 of power element I15. When theforce exerted by the expanded fluid exceeds the opposing force exerted by the power element spring I65, the bellows I82 will bepompressed and will move the thrust mem- ..ber I84 inwardly to pivot the lever member I62 in a clockwise direction. The force exerted by the spring I65 acting to hold the valve member 24 closed isythus overcome by the power element which holds the lever member in the dotted position shown in Fig. 7, unless the pilot light becomes extinguished or the power element fails, in either event of which the spring I65 acts. through the lever member I62 to close the valve. However. removal of the holding force of the spring I65 will not cause the valve member to be opened, for the spring 245, Fig. 5 of the thermostat controlled valve actuating mechanism in casing I96 will be holding the valve member 24 seated through the medium of lever I94 and arm I92. The damper "heat motor 3I2 ofjcourse will be deenergized when the main manual switch 402 is open so that the spring 342', Figs 'l and 14, will be holding the stack damper 286 in open position, and the switch contacts 364, 365v in engagement with the contacts 360, 36L respectively. When the manual switch 402 was closed to render the apparatus eifective, room thermostat I5 became operable to control the operation of the fuel and air control device I3. When the:room thermostat blade 392 is in engagement with the Contact member 396, as

make contact with the contact member 396 at say 78 F., and to make contact with the satisfied or .no-heat-demand contact member 393 at say 71 F. When the thermostat blade 392 is in contact with the contact member 396 as on a demand for heat, and assuming the valve l1 to be closed and the damper 286 to be open, then with the manual switch 482 closed and the circuit through the primary .385 of transformer 384, completed through lead wires 381, 388, the following secondary circuit will be established: from the sec- 18 ondary 388 through lead wire 389, terminal 318 on the panel board, jumper strip 391, terminal 318, lead wire 398, thermostat blade 392, contacts 396,

394, lead wire 399, terminal 314, jumper strip 319,

switch contacts 388, "384, switch strip 383, con- 20 tacts ass, 36I, jumper strip 318, terminal post 3",

lead wire 483, to one of the terminals 222, see Figs. 4 and 5, of the resistance coil'2l9 of the heat motor. for valve arm I92 and damper arm I94, and from the other termial 222, through lead wire 484, the terminal pos 318 of the terminal board 288, jumper strip 481, terminal 369, jumper wire 48I through closed manual switch 482, terminal 311, and lead wire 398 to the secondary 386 of the transformer 384. The resistance coil 2I9 of the heat motor I95 being thus energized, generates heat and heats the fluid in the bulb 2 I 6 which expands and exerts its force to compress the bellows 288, see Fig. 5, to overcome the spring 245 and move air damper lever I94 and valve lever I92 in a clockwise direction, facing Fig. 3, so that the air inlet draft damper I2, Fig. 2, and the valve member 24 of gas valve I1 are opened, and circuit is broken at tiltswitch I6. Gaseous fuel now flows through the open valve I1 to the main 4o burner 3 and is lighted by the pilot burner 5. The

burner then heats the heat conveying medium, such as air or any other suitable medium,,for conveying the heat to a room or other enclosed space to be heated. As the temperature in the furnace bonnet 1 increases, the expansible fluid in the bulb 63 is expanded exerting its force to compress the bellows 58. When the bellows 58 is compressed the thrust member 65 is urged into engagement with the lever member I88 and pivots so the lever members I88 and H5 in unison to throttle the valve member in accordance with furnace bonnet temperature. As previously mentioned, only the lever member H5 engages the valve member during Qe throttling action, but

.55 when the bonnet temperaturerises to a predetermined temperature the lever member l88 acts to close the valve with a snap action, or to seat on the closed valve member with a hammer blow ii the thrust member I31 is in its downmost adjusted 80 position to provide throttling to full-closed valve pmsition. The regulation or movement of valve member 28 toward open and closed position will of course continue under the control of power element 53 and in accordance with bonnet temperature as long as the room thermostat I5 is calling for heat.

When the room thermostat I 5 becomes satisfied the thermostat blade 392 will move out of 0 engagementwith the contact member 394 and 75 gized. The power element of the actuating through levers I92 to I89 to seat and to hold thevalve member 24 closed. When the lever member I94 is pivoted upwardly by the spring 248, the tilt switch I8 is tilted such that its contact members 21I and 218 move into contact, and when this occurs the following circuit is completed to the heat motor or the damper actuating mechanism: From the secondary 388 of transformer 384 to the lead wire 388, terminal post 316, jumper strip 391, lead wire 398, thermostat blade 392, contact members 388, 393, lead wire 488, jumper strip 488, jumper wire 388, to one of the. terminals 328, through the resistance coil 32I, to the other resistance coil terminal 328, to lead wire 38!, to terminal 388, lead wire 488 to the tilt switch terminal 28I, through the closed tilt switch and terminal 282, lead wire 488, terminal 389 of the terminal board 288, jumper wire 48I through the closed manual switch 482 to the terminal 311 and from terminal 311 through lead wire 398 to the transformer secondary 286. The resistance coil 32I of the damper heat motor is now energized and heat is generated which heats the expansible fluid in the bulb 3I8, the expanding fluid exerting its force to compress the bellows 3I4. .When the force exerted by the expanding fluid exceeds the force exerted by the coil spring '342 the damper motor power element will pivot the lever member 348 in a counterclockwise direction, as seen in Figs. 1 and 14. The damper member288 will then be closed to prevent the escape of heat through the chimney during the oil-cycle oi. operation of the heating apparatus and when the damper is closed, contact will be broken between the pairs of contact members 38I, 388 and 368, 384. Separation of the contact members 38I, 388 and 388, 364 respectively opens the circuit to the fuel and air supply control device I3 so that the furnace cannot be started while the damper 288 is in closed position.

When the room thermostat again becomes dissatisfied it breaks contact with contact member 393 and makes contact with contact member 394. Disengagement of the contacts 395 and 393 opens the circuit to the damper heat motor to deener gize the resistance coil 32I. The fluid .in the damper power element then begins to contract with corresponding and gradual diminishing of,

into engagement or contact with the contact members 388 and 38I respectively. When contact is made by the contact members 38I, 388 and 388, 388, the circuit is complete to the heat -motor- I98 of the valve I1 to permit flow of fuel to the main burner 3, to open the air damper l2, and to actuate the tilt switchi8 to break'circuit to the damper heat motor coil 32k What I claim and desire to secure by Letters Patent of the United States is:

1. In a heating apparatus, automatically operable means for controlling a fuel supply, temperature responsive means operatively to.

and controlling said means, an automatically actuated flow controlling damper, means operable to actuate said damper, means operable upon movement of said damper to open position to render said responsive means effective to control said supply means, means operatively connecting said responsive means to said damper actuating means, and means operable upon actuation of said supply means to render said responsive means effective to control said damper actuating means.

2. In a heating apparatus, fuel supply means, means operable to actuate said supply means, a flow controlling damper, means operable to actuate said damper, temperature responsive means having a first position for rendering said supply actuating means effective and having a second position for rendering said damper actuating means effective to close said damper, safety means operable upon actuation of said supply means and having a position to render control by said responsive means ineffective in said second position, and a second safety means operable with said damper and having a position to render control by said responsive means ineffective in said first position.

3. In a heating apparatus, a fuel supply controlling valve, temperature responsive means operable to regulate the supply of fuel by said valve, means holding said valve closed, temperature controlling means, actuating means operable by said controlling means to overcome said holding means so that said regulating means can actuate said valve, a flow controlling damper, damper closing means, means operable by said actuating means to render said damper closing means effective, and means operable upon movement of said damper toward open position to render said controlling means effective to control said actuating means.

4. In a heating apparatus, a fuel supply valve, a flow controlling damper, an electric switch having two circuit controlling positions, electrical means operable to actuate said valve and having a circuit energized in one position of said switch, electrical means operable to actuate said damper and having a circuit energized in another position of said switch, safety switch means in said valve circuit and closed upon opening movement of said damper, and safety switch means in said damper circuit closed upon closing movement of said valve. I

5. In a heating apparatus, a burner having an air inlet, a valve controlling the fuel supply to said burner, a damper controlling the outlet flue from said burner, a damper for said air inlet, an

electrically heated expansion motor operable to actuate said valve, an electrically heated expansion motor operable to actuate said flue damper, a room thermostat having one circuit controlling said valve motor and having another circuit controlling said flue damper motor, a safety switch in said flue damper motor circuit and opened on opening movement of said inlet damper, and a safety switch in said valve motor circuit and closed on opening movement of said flue damper.

6. In a heating apparatus, heating means having an outlet flue, automatically operable means to supply fuel to said heating means, means to energize said automatic means, automatically actuated means' controlling flow through said flue, operating means to actuate said flow controlling means to discontinue flow through said flue, means operable upon establishment of flow through said flue to render said fuel supply controlling means effective, and means operable upon operation of said supply means to supply fuel to render said operating means inefi'ective.

7. In a heating apparatus, heating means having an outlet flue, means to supply fuel to said means, means controlling said supply means, means to discontinue flow through said flue, means controlling said flow discontinuing means, operating means having a first position for rendering said supply controlling means effective and having a second position for rendering said flow controlling means effective to operate said discontinuing means, safety means operable upon operation of said supply controlling means to supply fuel to render said operating means ineffective in said second position, and a second safety means operable upon operation of saidflow controlling means to discontinue flow to render said operating means ineffective in said first position.

8. In a heating apparatus, heating means having a combustion chamber, means to supply fuel to said heating means, means controlling flow through said chamber, operating means having two controlling positions, means operable to actuate said supply means upon movement of said operating means to one of said positions, means operable to actuate sail flow controlling means upon movement of said operating means to the other of said positions, safety means to render said actuating means for said supply means ineffective upon operation of said flow controlling means to discontinue flow, and safety means to render said actuating means for said flow controlling means ineffective upon operation of said supply means to supply fuel.

EARN'EST J. DILLMAN. 

